Search Publications
Identification of Kinetic Alfvén Wave Turbulence in the Solar Wind
Bale, S. D.; Chen, C. H. K.; Mozer, F. S. +4 more
The nature of small-scale turbulent fluctuations in the solar wind is investigated using a comparison of Cluster magnetic and electric field measurements to predictions arising from models consisting of either kinetic Alfvén waves or whistler waves. The electric and magnetic field properties of these waves from linear theory are used to construct …
Global model of lower band and upper band chorus from multiple satellite observations
Meredith, Nigel P.; Horne, Richard B.; Thorne, Richard M. +4 more
Gyroresonant wave particle interactions with whistler mode chorus play a fundamental role in the dynamics of the Earth's radiation belts and inner magnetosphere, affecting both the acceleration and loss of radiation belt electrons. Knowledge of the variability of chorus wave power as a function of both spatial location and geomagnetic activity, re…
Large-scale electron acceleration by parallel electric fields during magnetic reconnection
Egedal, J.; Daughton, W.; Le, A.
Magnetic reconnection is a process by which the field lines of a magnetized plasma undergo dramatic realignment, releasing large amounts of energy. Large-scale simulations of reconnection events in the Earth's magnetosphere suggest that this process takes place over much greater distances than previously expected.
Local Kinetic Effects in Two-Dimensional Plasma Turbulence
Veltri, P.; Califano, F.; Servidio, S. +1 more
Using direct numerical simulations of a hybrid Vlasov-Maxwell model, kinetic processes are investigated in a two-dimensional turbulent plasma. In the turbulent regime, kinetic effects manifest through a deformation of the ion distribution function. These patterns of non-Maxwellian features are concentrated in space nearby regions of strong magneti…
Particle Acceleration in the Magnetotail and Aurora
Zelenyi, L. M.; Baker, D. N.; Artemyev, A. V. +3 more
This paper deals with acceleration processes in the magnetotail and the processes that enhance particle precipitation from the tail into the ionosphere through electric fields in the auroral acceleration region, generating or intensifying discrete auroral arcs. Particle acceleration in the magnetotail is closely related to substorms and the occurr…
Electric structure of dipolarization front at sub-proton scale
André, M.; Vaivads, A.; Huang, S. Y. +2 more
Using Cluster data, we investigate the electric structure of a dipolarization front (DF) - the ion inertial length (c/ωpi) scale boundary in the Earth's magnetotail formed at the front edge of an earthward propagating flow with reconnected magnetic flux. We estimate the current density and the electron pressure gradient throughout the D…
Intermittent Dissipation at Kinetic Scales in Collisionless Plasma Turbulence
Matthaeus, W. H.; Chapman, S. C.; Daughton, W. +6 more
High resolution kinetic simulations of collisionless plasma driven by shear show the development of turbulence characterized by dynamic coherent sheetlike current density structures spanning a range of scales down to electron scales. We present evidence that these structures are sites for heating and dissipation, and that stronger current structur…
Solar Wind Turbulent Spectrum at Plasma Kinetic Scales
Maksimovic, M.; Alexandrova, O.; Mangeney, A. +2 more
The description of the turbulent spectrum of magnetic fluctuations in the solar wind in the kinetic range of scales is not yet completely established. Here, we perform a statistical study of 100 spectra measured by the STAFF instrument on the Cluster mission, which allows us to resolve turbulent fluctuations from ion scales down to a fraction of e…
Occurrence rate of earthward-propagating dipolarization fronts
André, M.; Vaivads, A.; Huang, S. Y. +2 more
The occurrence rate of earthward-propagating dipolarization fronts (DFs) is investigated in this paper based on the 9 years (2001-2009) of Cluster 1 data. For the first time, we select the DF events by fitting the characteristic increase in Bz using a hyperbolic tangent function. 303 earthward-propagating DFs are found; they have on ave…
Pitch angle distribution of suprathermal electrons behind dipolarization fronts: A statistical overview
Daly, P. W.; André, M.; Vaivads, A. +5 more
We examine the pitch angle distribution (PAD) of suprathermal electrons (>40 keV) inside the flux pileup regions (FPRs) that are located behind the dipolarization fronts (DFs), in order to better understand the particle energization mechanisms operating therein. The 303 earthward-propagating DFs observed during 9 years (2001-2009) by Cluster 1 …